This invention relates to a method and device for detecting the ignition of an explosion within a combustible gas mixture, e.g., in a gas stream flowing through a reaction vessel, and locating the point of ignition. The invention also relates to a process for producing maleic anhydride using the ignition detection method and device.
A number of industrial chemical reactions occur under conditions which occasionally result in events such as deflagrations or detonations which, though typically not catastrophic, can result in costly process interruptions, waste of reactants, and the like. For example, in the catalytic partial oxidation of hydrocarbons, a combustible mixture of hydrocarbon and air may be introduced into the reaction zone. If conditions are not adequately controlled ignition can occur, resulting in a deflagration. It is desirable to detect the point of ignition of such events so that steps can be taken to minimize the risk of future events. Identifying the point of ignition may help identify locations where surface chemistry or local stream parameters are conducive to ignition. However, reaction vessels are typically closed and the propagation of flame fronts associated with such events are rapid, so that it is often not possible to locate the ignition point visibly or easily by other means.